In a modem automotive vehicle, the HVAC unit includes an evaporator core mounted in a housing which receives an air steam from a blower motor also mounted in the housing. Since prolonged continuous use of the air conditioning portion of the HVAC unit can cause freezing of the evaporator core, a temperature probe is typically inserted in the core fins at the location of the coldest spot on the evaporator core. The probe is in the form of thermocouple having a flexible conduction extending out of a rigid probe sensing head. As shown in FIG. 1, the thermocouple conduction extends to a plug which is mounted in an opening in the HVAC housing generally immediately adjacent the position of the probe. An electrical connector is also mounted on the plug, as shown in FIG. 2, for connection to an external conductor for transmission of the probe sense output to a remote controller. This enables the operation time of the HVAC compressor to be controlled to prevent freezing of the evaporator core.
However, serviceability of the probe is an essential requirement in that the probe must be capable of easy removal and replacement during the expected long term use of the vehicle. Easy access to the probe and/or plug from underneath the instrument panel is necessary if the time consuming and costly need to remove the entire instrument panel in order to replace the HVAC core temperature probe is to be avoided.
As shown in FIGS. 1 and 2, and partially in FIG. 6, certain HVAC housing designs, can result in a minimal amount of space available for access to the probe plug. The elongated shape of the probe sensing head requires a sufficient space to pull the probe out through the access opening in the housing. When such space is not available, as shown in the example depicted in FIGS. 1 and 2, a vehicle no-build condition exists.
Thus, it would be desirable to provide a vehicle HVAC evaporator core probe assembly and assembly method which provides easy serviceability of the temperature probe at any time during the life of the vehicle without requiring removal of the entire instrument panel.
The present invention is a vehicle HVAC evaporator temperature probe apparatus and assembly method.
In one aspect of the invention, the HVAC evaporator probe temperature apparatus is adapted for mounting in an HVAC housing having an evaporator core, a first aperture formed in the housing, and a second aperture formed in the housing spaced from the first aperture and disposed in proximity with a cold temperature location in the core. The apparatus includes a temperature probe having a sensing end adapted to be inserted into an evaporator core, a conductor having first and second ends, the first end connected to the temperature probe sensing end, an electrical connector connected to the second end of the conductor, and a seal member mounted on the conductor intermediate the first and second ends for sealingly mounting the conductor in the first aperture such that the electrical connector is disposed exteriorly of the housing in which the temperature probe is mounted.
Preferably, the seal member is fixedly mounted on the conductor and formed for a snap-fit mount in the first aperture.
In another aspect, the present invention is an HVAC apparatus which includes a housing having an exterior wall, an evaporator core mounted in the housing, a first aperture formed in the exterior wall of the housing, a temperature probe having a sensing end mounted in the evaporator core, an electrical conductor having first and second ends, the first end connected to the temperature probe sensing end, an electrical connector connected to the second end of the conductor, and a seal member mounted on the conductor intermediate the first and second ends for sealingly mounting the conductor in the first aperture such that the electrical connector is disposed exteriorly of the housing in which the temperature probe is mounted.
In this aspect, the seal member is preferably fixedly mounted on the conductor and formed for a snap-fit mount in the first aperture.
A second aperture is also formed in the wall spaced from the first aperture. The second aperture is disposed in proximity with the mounting position of the temperature probe sensing end in the evaporate core and removably receive a closure member.
The present invention also defines a method for mounting an HVAC evaporate core temperature probe in an HVAC housing having a first aperture in an exterior wall. The method comprises the steps of:
inserting a temperature probe sensing end into the evaporator core prior to mounting the evaporator core in the housing;
mounting the evaporator core in the housing;
routing an electrical conductor extending from the probe sensing end through the housing such that an electrical connector connected to an opposite end of the conductor is disposed exteriorly through the first aperture in the housing wall; and
sealingly closing the first aperture in the housing wall.
Preferably, the method also includes the step of pre-mounting the seal member on the conductor. The pre-mounting of the seal member also includes the step of fixedly mounting the seal member on the conductor.
The method also includes the step of:
forming a second aperture in the housing wall spaced from the first aperture and disposed in proximity with the mounting position of the temperature probe sensing end in the evaporator core when the evaporator core is mounted in the housing; and
withdrawing the temperature probe sensing end from the evaporator core and the housing through the second aperture.
In this aspect, the method also includes the step of mounting a removable closure member in the second aperture to sealing close the second aperture.
The present method is also devised for removing a temperature probe from the evaporator core and comprises the steps of:
forming a second aperture in the housing wall spaced from the first aperture and disposed in proximity with the mounting position of the temperature probe sensing end in the evaporator core when the evaporator core is mounted in the housing; and
withdrawing the temperature probe sensing end from the evaporator core and the housing through the second aperture.
The present method also is devised for installing a new probe assembly in the housing when an existing temperature probe assembly is to be removed from the housing. In this aspect, the method further comprises the step of:
installing a new probe assembly in the housing when an existing temperature probe assembly is to be removed from the housing, the method comprising the steps of:
connecting the sensing end of a new temperature probe apparatus to a portion of the existing temperature probe in the housing;
pulling the new probe assembly into the housing through the first aperture simultaneous with removing the existing probe apparatus through the second aperture in the housing;
separating the new probe apparatus from the old probe apparatus;
mounting the sensing end of the temperature probe in the evaporator core;
mounting the seal member in the first aperture in the housing; and
mounting a seal member in the second aperture in the housing.
The apparatus and method of the present invention uniquely enable an HVAC evaporator core temperature probe to be expeditiously mounted in an HVAC housing while enabling the temperature probe to be easily removed from the housing, while the housing is still mounted in its mounting position in a vehicle through an easily accessible opening. The present invention also defines a unique method of mounting a replacement temperature probe in an HVAC housing when an existing temperature probe is to be removed from the housing. The method of mounting a new temperature probe in the housing takes place simultaneously with removal of the existing temperature probe from the housing thereby reducing repair time and labor costs.